USER_INTERRUPT (0x094) - 4.0 English

QDMA Subsystem for PCI Express Product Guide (PG302)

Document ID
PG302
Release Date
2022-05-20
Version
4.0 English
Table 1. User Interrupt (0x094)
Bit Default Access Type Field Description
[31:20] 0 NA Reserved
[19:12] 0 RW usr_irq_in_fun User interrupt function number
[11:9] 0 NA   Reserved
[8:4] 0 RW usr_irq_in_vec User interrupt vector number
[3:1] 0 NA   Reserved
[0] 0 RW usr_irq User interrupt. When set, the example design generates a user interrupt.

To generate a user interrupt:

  1. Write the function number at bits [19:12]. This corresponds to the function that generates the usr_irq_in_fnc user interrupt.
  2. Write MSI-X Vector number at bits [8:4]. This corresponds to the entry in the MSI-X table that is set up for usr_irq_in_vec user interrupt.
  3. Write 1 to bit [0] to generate user interrupt. This bit clears itself after usr_irq_out_ack from the DMA is generated.

All three above steps can be done at the same time, with a single write.

The user interrupt timing diagram is shown below:

Figure 1. Interrupt